Technical Field
The present disclosure relates to the field of methods for removing cationic dyes from an aqueous solution. More specifically, the present disclosure relates to a method of removing one or more cationic dyes from an aqueous solution using an adsorbent comprising a water-insoluble membrane comprising cross-linked humic acid, at least one alginate, and hydroxyethyl cellulose disposed on a substrate.
Description of the Related Art
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, is neither expressly nor impliedly admitted as prior art against the present invention.
Dyes are commonly used in textile, pharmaceutical, food, tanning and paper industries (See M. N. Ashiq, M. Najam-Ul-Haq, T. Amanat, A. Saba, A. M. Qureshi, M. Nadeem, Removal of methylene blue from aqueous solution using acid/base treated rice husk as an adsorbent, Desalination and Water Treatment, 49 (2012) 376-383. M. T. Yagub, T. K. Sen, S. Afroze, H. M. Ang, Dye and its removal from aqueous solution by adsorption: a review, Adv. Colloid Interface Sci., 209 (2014) 172-184. J. R. Deka, C. L. Liu, T. H. Wang, W. C. Chang, H. M. Kao, Synthesis of highly phosphonic acid functionalized benzene-bridged periodic mesoporous organosilicas for use as efficient dye adsorbents, J. Hazard. Mater., 278 (2014) 539-550, each incorporated herein by reference in their entirety). Types of dyes include basic and or cationic dyes which are positively charged stains that react with a material that is negatively charged. Cationic dyes typically contain amino groups, or alkylamino groups, as their auxochromes. Examples of cationic dyes are methylene blue, rhodamine B, crystal violet, basic fuchsin, safranin, pararosaniline, etc.
Waste water containing dyes has resulted in pollution of many water sources, including ground water and river water from which tap water and drinking water are obtained. Dyes affect the chemical oxygen demand (COD) and sunlight penetration in water, both of which have a detrimental effect on aquatic life (See K. Zhou, Q. Zhang, B. Wang, J. Liu, P. Wen, Z. Gui, Y. Hu, The integrated utilization of typical clays in removal of organic dyes and polymer nanocomposites, Journal of Cleaner Production, 81 (2014) 281-289, incorporated herein by reference in its entirety). Cationic dyes have such a high color intensity that even at trace levels, they impart color to water, making it undesirable for consumption. Although cationic dyes such as methylene blue (MB) and rhodamine B (RhB) are not as hazardous as azo or reactive dyes, acute exposure to them may result in serious health issues. Inhalation of MB can cause increased heart rate, and ingestion of MB may lead to vomiting, nausea, jaundice, tissue necrosis and quadriplegia (See A. Gürses, A. Hassani, M. Kiranan, Ö. Açili, S. Karaca, Removal of methylene blue from aqueous solution using by untreated lignite as potential low-cost adsorbent: Kinetic, thermodynamic and equilibrium approach, Journal of Water Process Engineering, 2 (2014) 10-21, incorporated herein by reference in its entirety). RhB is a common staining dye in biotechnology known to have neurotoxicity and carcinogenicity, and can cause irritation of the skin, eyes and respiratory tract (See H. Mittal, S. B. Mishra, Gum ghatti and Fe3O4 magnetic nanoparticles based nanocomposites for the effective adsorption of rhodamine B, Carbohydr. Polym., 101 (2014) 1255-1264. K. G. Bhattacharyya, S. SenGupta, G. K. Sarma, Interactions of the dye, Rhodamine B with kaolinite and montmorillonite in water, Appl. Clay Sci., 99 (2014) 7-17, each incorporated herein by reference in their entirety).
Because dyes are toxic and non-biodegradable, removal of dyes from water sources is necessary to provide clean and safe water and protect aquatic life (See N. Jain, A. Bhargava, J. Panwar, Enhanced photocatalytic degradation of methylene blue using biologically synthesized “protein-capped” ZnO nanoparticles, Chem. Eng. J. (Lausanne), 243 (2014) 549-555. Y. Li, Q. Du, T. Liu, J. Sun, Y. Wang, S. Wu, Z. Wang, Y. Xia, L. Xia, Methylene blue adsorption on graphene oxide/calcium alginate composites, Carbohydr. Polym., 95 (2013) 501-507, each incorporated herein by reference in their entirety).
It is an object of this disclosure to provide methods for removing cationic dyes from water or an aqueous solution using an adsorbent comprising a water-insoluble membrane comprising cross-linked humic acid, at least one alginate, and hydroxyethyl cellulose disposed on a substrate.